1. Field of the Invention
The present invention relates to an organic light-emitting diode and a display panel using the same, and especially to an organic light emitting diode having a carrier conversion layer and a display panel using the same.
2. Description of Related Art
An organic light-emitting diode (OLED) is a self-luminous light-emitting device, having advantages such as a wide viewing angle, high contrast, fast response, and high brightness, etc., and is capable of providing lights with various colors depending on the organic materials used.
The basic structure of a typical organic light emitting diode (OLED) includes a cathode, an organic material layer, and an anode, which are sequentially stacked on a substrate. In an OLED, electrons and holes are injected from the cathode and the anode respectively, and recombine in the organic material layer to emit light. To effectively inject the carriers from the electrode layer to the organic material layer, particularly from the cathode to the organic material layer, the metal with a low work function is generally employed to modify the junction between the cathode and the organic material layer, thereby improving the electron injection efficiency. However, this method may reduce light transmittance of the device, and the carrier injection efficiency is gradually reduced over operation time, thus reducing the service lifetime. In addition, considering the electron injection efficiency, a material with a low work function is generally selected as the electrode, thus limiting the material selection of electrode. In addition, this also increases the difficulty associated with integration of organic light-emitting diodes and other driving circuit elements (such as transistors).
Accordingly, what is needed is to develop an organic light-emitting diode having a long service lifetime, an improved integration ability with other components, and excellent carrier injection efficacy.